Category: Space Station

Although Discovery returned safely to Earth, there were still a few unfinished tasks. The astronauts on board the International Space Station picked up the torch, and wrapped them up in a 6.5 hour spacewalk on Friday. This helps prepare the station for the upcoming launch of Atlantis, to deliver the European Columbus module.

Discovery landed on Friday at the Kennedy Space Center in Florida, completing 15 days in space. In addition to bringing and installing the new Harmony module, the astronauts redeployed a solar array to a new location. And that’s where the problems happened. While they were unfolding the array, a guide wire was caught, and tore open a fold between solar panels.

The astronauts were were able to build “cufflinks” that reconnected the panels, but this additional spacewalk meant that other tasks couldn’t be performed.

The goal of Friday’s spacewalk was to wrap them up. Commander Peggy Whitson and cosmonaut Yuri Malenchenko went outside the station today to disconnect various electrical cables and stowing them away. Some route power to visiting shuttles the others connect the shuttle’s docking port to the Destiny laboratory.

On Monday, flight engineer Dan Tani will use the station’s robotic arm to move the shuttle’s docking port from its current location on Destiny over to the newly attached Harmony module.

And then on Wednesday, another spacewalk will move the Harmony node to its permanent location on the Destiny module.

Two additional spacewalks are planned to hook up power, cooling and data connections to the Harmony module.

This crew is going to be busy.

Original Source: NASA Station News

NASA’s space shuttle Discovery touched down in Florida today, landing at Kennedy Space Center, and wrapping up a successful assembly mission to the International Space Station. The shuttle’s wheels touched pavement at 1:01 p.m. EST, with Commander Pam Melroy and Pilot George Zamka at the controls.

During their 15 days in space, the crew of STS-120 covered more than 10 million km (6.2 million miles). They attached the newly delivered Harmony Node 2 module, and relocated P6 truss. During the construction, one of the station’s solar arrays was torn, and so the astronauts completed an extra spacewalk to repair the damage.

In addition to the crew members who flew to the station, Discovery was carrying a special guest back to Earth: astronaut Clay Anderson. He spent the last 5 months living and working on board the station, and required a special reclining chair during re-entry to get used to the strength of Earth’s gravity after so much time being weightless.

Despite the resourceful repairs to the station’s power generating solar array, NASA managers are concerned that construction on the station may lag. The problems during Discovery’s mission has delayed other work on the station, and now construction is nearly a work behind schedule. The other shuttle missions are crammed together so tightly that there’s hardly any slack time. An upcoming mission to launch the European Columbus module may be in jeopardy.

Another problem is the metal fragments discovered in a wheel that rotates the station’s solar arrays. Without them rotating to always face the Sun, the station won’t be able to generate enough power to accommodate a Japanese laboratory due to arrive in April, 2008.

The next mission – STS-122 – will bring the space shuttle Atlantis back to the International Space Station. It’ll be carrying the European Columbus laboratory. It’s scheduled to launch on December 6th, but could get pushed back.

Original Source: NASA’s Shuttle Blog

The space shuttle Discovery pulled away from the International Space Station Monday morning, wrapping up an eventful 11-day visit. The 7 astronauts completed their scheduled events as well as an unplanned fix to the station’s torn solar panel – created when the solar array was moved to a new location and opened up.

After pulling away, Discovery made one last flyby of the station, taking photographs that NASA engineers can study back on Earth. Then the shuttle retreated to perform one final inspection of the shuttle’s heat shield.

If all goes well, Discovery will land back at the Kennedy Space Center in Florida at 1:02 p.m. EST on Wednesday.

The astronauts completed one last spacewalk on Saturday, repairing the torn solar wing. This was critical. With the solar panels damaged, the wing couldn’t be fully deployed. And without being fully deployed, NASA couldn’t risk continuing the station’s construction.

Astronaut Scott Parazynski attached himself to an extension boom brought by Discovery, and was maneuvered out to the repair site on the solar array. He installed five homemade braces – “cufflinks” – that helped support the array, and realign the torn panels. In addition to reconnecting the torn panels, he also cut the guidewires that had snagged on the unfolding array in the first place.

The repair job was quite dangerous, because the solar array was charged, and would have given Parazynski a shock if he accidently touched it. He did have insulated gloves and boots, but he worked carefully, mindful of the risks.

“What an accomplishment,” he said, after fixing the panel and then watching it reach its full 33 metre (110 feet) length.

Original Source: NASA Shuttle News

With all that fancy camera equipment, the NASA astronauts took more detailed images of the damaged solar panels on the International Space Station. These are the images NASA engineers will use to figure out what kind of risk the panel faces if it’s fully deployed, and what kinds of repairs could be done to minimize the damage. Oh, and the next spacewalk has been delayed to Friday.

Because of the damaged panel, managers at NASA decided to change up their plans for the next few days. Instead of their originally scheduled spacewalk, to demonstrate tile repair techniques, the astronauts will now be focusing on damage assessment and repair.

They’ve got to have another look at the malfunctioning rotary joint on the right-hand side of the station. The joint is currently parked because the mechanism was vibrating too much, and consuming energy. When astronaut Daniel Tani looked inside, he found evidence that the mechanism was grinding together, shedding tiny metal shavings. During the latest spacewalk, the astronauts looked at the right-hand side and found that it was working fine.

The tear in the solar array happened during the latest spacewalk on Tuesday. The astronauts had just completed the redeployment of the solar array to its new home, and were extending the panels. A portion of the panels were invisible in the glare of the Sun, so the astronauts didn’t notice its damage until it was too late.

The 80 cm tear in the array was probably caused when a guide wire snagged one of the hinges that allow the panels to fold up tight. As the panel was extended, one flap hooked onto this guide wire and tore along the fold.

NASA is now in a bit of a bind. Although they’re generating power now, they’ll work best when fully extended. There are also structural problems with having the array not fully extended. For the time being, both rotary joints have been locked shut, protecting the panels, but reducing the station’s ability to generate power.

Original Source: NASA News Release

The third spacewalk of STS-120 involved moving a large solar array panel to a new position on the International Space Station. Just as the supposedly successful spacewalk was coming to a close, the astronauts noticed that at least one panel on the array has torn. The astronauts halted extending the array, took a bunch of photographs, and now NASA engineers are working to figure out what to do next.

They were so close. Astronauts Scott Parazynski and Doug Wheelock had just finished installing the P6 truss with the help of the station and shuttle’s robotic arms. Completing this task had been done over the course of three different spacewalks – over 7 hours of work on today’s walk alone.

As the solar array was almost completely unfurled, the astronauts noticed that a section about 80 cm (2.5 feet) in length had torn. They didn’t notice the damage earlier, because sunlight was obscuring the view to the torn section.

Once they noticed the damage, the astronauts halted the operation, and reported the problem to NASA. Then they took a series of photographs so that engineers can study the damage and determine what will happen if they try to continue opening up the panels.

NASA has already decided to add an extra day to Discovery’s mission, giving the astronauts an extra spacewalk can be performed on Thursday. During this trip outside the station, the astronauts will study the troublesome joint that was found damaged during the second spacewalk of the mission.

Mike Suffredini, NASA’s International Space Station, isn’t worried about the power generating capacity of the panels, “if we get the array down and we cut the snag and we figure out how to reinforce it, we’ll redeploy the array. It’s giving all the power we need. It doesn’t have to look good; it’s not about style points.”

During today’s spacewalk, the astronauts also examined the port rotary joint, and didn’t find the same evidence of metal filings that were discovered in the starboard joint. Scott Parazynski described the joint’s race rings as “nice and clean.”

Discovery is now due to undock from the space station on Monday, and return to Earth on November 7th.

Original Source: NASA News Release

NASA astronauts added the newest module to the International Space Station on Friday morning, clearing the way for several new laboratory modules and increasing the sleeping capacity. Astronauts Scott E. Parazynski and Col. Douglas H. Wheelock spent their morning on Friday, suspended above the planet, attaching the newly delivered Harmony module to the station. During the second spacewalk on Sunday, the astronauts discovered damage to one of the joints that orient the station’s solar arrays.

First Spacewalk – Friday
Once the shuttle docked on Thursday, the first scheduled spacewalk began early the next day. Parazynski and Wheelock went outside the station at 6 a.m. EDT, and prepared Harmony for its removal from the shuttle’s payload bay.

Inside the station, Stephanie D. Wilson and Daniel M. Tani operated the station’s robotic arm, to help remove the module from the shuttle’s cargo bay and transfer it over to the station.

The spacewalk itself went quickly, and mostly without incident. The astronauts struggled briefly to remove some of holding bolts and hose connectors. And there were a few situations where frozen ammonia drifted away from some of the hoses. This ammonia could contaminate the station’s atmosphere if it got back inside, so the astronauts carefully avoided coming into contact with any of the substance.

Second Spacewalk – Sunday
For the second spacewalk on Sunday, Scott Parazynski was joined by Daniel M. Tani. Their task was to unbuckle a solar array atop the station so that it can be relocated. They also began outfitting the exterior of the newly attached Harmony module.

After removing a protective cover, Tani discovered what appeared to be metallic shavings in one of the station’s rotating joint assemblies. He collected up some samples with tape so that engineers can study it, and figure out what could be going on. Station controllers had noticed that a joint on the right-hand side of the station was experiencing unusual vibrations as it rotated, so these two events could be connected.

The best theory right now is that the foil backing on an aluminum cover is rubbing against the mechanism that turns the station’s solar arrays to orient towards the Sun. This material is shredding off the cover and getting into the mechanism.

NASA is considering whether they’ll have the astronauts open up all 21 covers to see if any are the source of the damage. This could be done during a currently planned spacewalk, or it could become another spacewalk all on its own. Even if the source of the metal is discovered, it might be impossible to clean.

Original Source: NASA Station Coverage